Deciding which energy crop to choose for your plantation is difficult, as most options have favourable features. Two of those options are Arundo donna and Miscanthus giganteus – similar crops that are both excellent for bioenergy, furniture or paper production. However, you are often faced with the trouble of choosing, so we put together 12 REASONS why you should plant Arundo instead of Miscanthus to produce biomass more efficiently.
1. Biomass yield
It is generally stated that Arundo has a higher biomass yield than Miscanthus. In the case of a fall harvest, 15-41 dry tonne per hectare, whilst in the case of a winter harvest, 21-49 dry tonne per hectare was reported. The biomass yield of Miscanthus was reported to be only 2.4 dry tonne per hectare during the first year, while it increased to 14.28, 19.77, and 29.43 dry tonne per ha, respectively, from the second to the fourth year. On wetlands Arundo achieved more than two times of average dry biomass production than Miscanthus.
2. Flood tolerance
Arundo was reported to be more resilient to moisture stresses than Miscanthus, especially in rhizome persistence. 3 days after a flood treatment, Miscanthus became chlorotic and its growth temporarily stopped.
3. Drought tolerance
Arundo was found to be more tolerant to drought than Miscanthus. As for rhizome survival, the rhizomes of the giant reed grass were also found to be more resilient to drought stress in comparison to Miscanthus. Fragments put under severe drought showed low rates of survival for both species, nevertheless, the survival rate was 50% for Arundo donax and 0% for Miscanthus. It has also been proven that Arundo donax becomes drought tolerant after only one year of establishment.
4. pH tolerance
Arundo was found to tolerate wider ranges of pH and salinity than Miscanthus (a pH in the range of 5.0 to 8.7).
5. Planting density
The recommended planting density for Arundo is 10,000 plants/ha, while Miscanthus requires 30,000 plants/ha. If you plant Arundo, you require one third less plant/ha compared to Miscanthus, thereby saving significant cost of propagues.
6. Number of harvest per year
Two harvests per year are feasible for Arundo but not recommended for Miscanthus. This means that your potential biomass yield annually is also significantly higher – a feature that is especially crucial for the production of biogas or bioethanol, when the plant is harvested when it is still green.
7. Total energy output and net energy output
Due to the higher biomass yield that was obtained from Arundo, the total energy output and net energy output of Arundo were higher than those of Miscanthus. The Energy balance (Energy Output – Energy Input) is 4654.4 GJ ha-1 for Arundo which is higher than both Miscanthus (3025.3 GJ ha-1) and Switchgrass (1760.3 GJ ha-1)
8. Impact on soil quality
Arundo was also reported to enhance the bacterial and fungal growth in the soil. Arundo was also found to have a higher ability than Miscanthus in increasing soil organic carbon accumulation. Overall, Miscanthus’ effect on soil quality cannot be compared to that of Arundo.
9. Phyto-remediation ability
Arundo is likely to have a better ability for trace element removal due to its higher biomass yield. On wetlands, Arundo achieved more than two times the average dry biomass production than Miscanthus. Moreover, the N and P phyto-uptake of Arundo were also significantly higher than other plants.
10. Bioethanol yield
Higher ethanol yield was obtained from Arundo compared to Miscanthus mainly due to the higher sugar yield from Arundo. Arundo donax has a potential yield of 265 kg ethanol per dry metric ton of raw material, thanks to its sugar yield, which is way higher than that of Miscanthus.
11. Biogas production
From raw biomass, 151-391 L per kg VS (volatile solid) for Arundo is achieved, whilst 175-333 L per kg VS is produced from Miscanthus. However, harvest time may affect the total energy potential per hectare by altering both the methane yield per unit biomass and the total biomass yield per hectare. For Arundo, a double harvest in the early summer and late autumn was reported to increase the methane yield per hectare by 20–35% compared to the most productive single harvest.
12. Furniture production
Arundo showed a better performance than Miscanthus in production of particle boards, paper and XOS – but its lignin had a lower effectiveness than that of Miscanthus as a humic substrate.